Rotary hammer drill bit



Aug. 29, 1961 R. o. DULANEY 2,993,035

ROTARY HAMMER DRILL BIT Filed June 14, 1960 5 INVENTOR. 25 24 EICHAZD O.Dux. Am-LY 2,998,085 ROTARY HAMMER DRILL BIT Richard 0. Dulaney, 1403Continental National Bank Bldg, Fort Worth 2, Tex. Filed June 14, 1960,Ser. No. 35,990 3 Claims. (Cl. 175100) This invention relates to Welldrilling implements, and more particularly to a rotary drill hammerimplement of the fluid-actuated type adapted to dig by a combination ofrotary scraping action and pounding action.

A main object of the invention is to provide a novel and improved rotarydrill hammer for use in well drilling and similar operations, the devicebeing simple in construction, being easy to install, and beingsubstantially automatic in operation.

A further object of the invention is to provide an improved welldrilling device of the rotary hammer type, the device involvinginexpensive components, being durable in construction, being usableeither with hydraulic or pneumatic fluid, and providing efiicientutilization of the pressure fluid driving same.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

FIGURE 1 is a vertical cross sectional view taken through an improvedrotary drill hammer constructed in accordance with the presentinvention, shown with the main casing thereof elevated.

FIGURE 2 is a vertical cross sectional view, similar to FIGURE 1, butshowing the vertical casing lowered to provide the pounding impact,immediately preceding the chopping action produced by the descent of thehammer member of the device.

FIGURE 3 is an enlarged horizontal cross sectional view takensubstantially on the line 33 of FIGURE 2.

FIGURE 4 is an enlarged horizontal cross sectional view takensubstantially on the line 44 of FIGURE 2.

FIGURE 5 is an enlarged horizontal cross sectional view takensubstantially on the line 55 of FIGURE 2.

Referring to the drawings, 11 generally designates an improved rotarydrill implement according to the present invention, the implementcomprising a vertical main casing 12 to the top end of which isconnected a head member 13, the head member being formed with thereduced collar portion 14 which is threadedly engaged inside the top endof main casing 12. Head portion 13 is further formed with a taperedconnection portion 15 formed with external screw threads, whereby it maybe fastened in the conventional manner to a supporting pipe section, andwhich may be thus connected to a suitable fluid pressure source, forexample, to a source of drilling fluid under pressure.

The head member 13 is formed with a plurality of vent openings 16 toallow the drilling fluid to at times be vented from the main casing, aswill be presently explained.

Secured in the lower end of the main casing 12 is a bearing collar 17,said bearing collar having the reduced externally threaded top portion18 which is threadedly engaged in the bottom end portion of the maincasing 12. The collar member 17 is provided with the equally spaceddepending guide fingers 19 and slidably engaging in vertical grooves 20formed in a first tool supporting tube 21 whose reduced top portion 22extends slidably through the bearing collar 17.

Secured in the tool supporting tube 21 is a first tool bit 23 whichcomprises a pair of diametrically opposed blade members 24, 24 formedwith the bottom cutting edges 25, 25 and spaced apart at their innervertical edges to define a vertical guide slot 26. Designated at 27 is asecond tool bit which is slidably engaged with the first rates Patent 0tool bit and which extends transversely thereto in the guide slot 26,the second tool bit being formed with the bottom cutting edge 28 whichis perpendicular to the cutting edges 25, 25 of the first tool bit 23.

The second tool bit 27 is provided at its top end with a hollow annularhead portion 29 which is threadedly engaged in the bottom end of asecond tool supporting tube 30 which extends slidably through the firsttool supporting tube 21, and which thus guides the second tool bit 27for vertical sliding movement with respect to the first tool bit 23.

The head member 29 is provided with the frusto conical intermediateportion 31 which is formed with a plurality of relatively small ventopenings 32 providing restricted venting of the pressure fluid.

Designated at 33 is a depending pressure fluid conduit which is axiallysecured in the head member 13 and which extends slidably into the secondtool bit supporting tube 30. Secured on the top end of the tube Silandin sliding engagement with the conduit 33 is the annular hammer member34. As shown in FIGURES l and 2, the hammer member 34 is of substantialvertical height, and acts as a guide sleeve for the secondtool-supporting tube 30. The hammer member 34 is formed at its bottomrim With a frusto conical annular valve surface 35 which is at timessealingly engageable with a mating frusto conical valve surface 36formed in the top rim of a valve ring 37. The valve ring 37 is slidablyengaged within a valve guide sleeve 38 which is secured to the top endof the first tool-supporting tube 21 by means of an annular connectingcollar 39. Thus, the guide sleeve 38 is threadedly engaged with the topend of the connecting collar 39 and the collar 39 is threadedly engagedon the top end portion of the first tool bit supporting tube 21 as shownat 40. The annular valve ring member 37 is yieldably connected to thecollar member 39 by coiled spring 41, the lower end of the spring beingconnected to the top of the collar member 39 and the top end of thespring being connected to the valve ring member 37, so that the springacts to bias the ring member to a predetermined position in the valvesleeve 38. As shown. the spring 41 is mounted axially inside the sleeve38 and surrounds the second tool bit supporting tube 30.

The collar member 39 is slidably engaged in the main casing 12 and isformed with a plurality of fluid passages 43 which establishcommunication between the space immediately below the collar member 39and the space within the valve sleeve 38.

Secured in the top portion of the sleeve 38 is a stop ring 44 whichlimits upward movement of the valve ring member 37. The firsttool-supporting tube 21 is formed with respective upwardly facingshoulders 45 which cooperate with the downwardly facing shoulders 46 onthe collar member 17 to support the main casing 12 on the firsttool-supporting tube 21 during the drilling action, namely, the rotarymovement of main casing 12. On the elevation of the main casing, the topsurface of the collar member, namely, the top surface of reduced portion18 thereof comes into engagement with the bottom surface of the collarmember 39, as shown in FIG- URE 1, blanking the passages 43.

When the casing 12 is lowered, the top portion 18 of collar member 17descends relative to the collar member 39, providing a space 47 betweenmember 39 and member 18, this space being placed in communication withthe space inside the valve sleeve 38 through the passages 43. The secondtool bit supporting tube 30 is formed with a plurality of vertical slots49 which register with a plurality of passages 50 formed in the upperportion of the first tool bit supporting tube 21, the registration beingeffective in the various difierent relative operating positions of themembers 30 and 32, because of the substantial vertical height of theslots 49. However, these ports are blanked in the elevated position ofthe casing 12 illustrated in FIGURE 1, since the member 17 moves into aposition covering the ports 50 as well as the bottom ends of thepassages 43.

FIGURE 2 illustrates the positions of the parts during the operation ofthe device, with the chopping tool bit 27 elevated. The elevation oftool bit 27 is caused by the pressure of the drilling fluid, whichpasses upwardly into the space beneath annular valve member 37, raisingsaid valve member 37 into sealing contact with annular surface 35 andelevating the hammer member 34. The upward momentum of the hammer membercauses it to continue to rise while spring 41 pulls valve member 37downwardly, releasing the pressure fluid and allowing it to travelupwardly toward the vent passages 16. The passages 43 are relativelyrestricted, so that a substantial building up of pressure may occurinside the tube 30, the pressure eventually reaching a sufficient valueto cooperate with the Weight of hammer member 34 to drive the member 30downwardly, causing the bit 27 to descend with substantial impact and toprovide a chopping action which cooperates with the scraping andpounding action provided by the main bit 23. The downward movement ofthe tube 30 moves the hammer member 34 downwardly so that the valvesurface 35 thereof may be brought once more into sealing contact withthe valve surface 36 of the ring 37, preparing the device for the nextcycle.

In the operating position of the casing 12, the pressure fluid acts onthe hammer member 34 through the ring 37, causing the ring to beelevated somewhat with the harn-v mer member, the spring 41 beingyieldable to permit such elevation of ring 37. As previously mentioned,a sufficient amount of momentum is delivered to the hammer member 34 toallow the hammer member to rise a substantial distance, the upwardmovement of the ring 37 being limited by the stop ring 44 provided inthe top end of the valve sleeve 38. As shown in FIGURE 2, sufficientclearance is provided between the ring 37 and the hammer member 34 toallow the pressure fluid to escape toward the vent passages 16, butthere is a sulficient delay to allow the building up of pressure insidethe tool bit supporting tube 30 to drive the second tool bit 27downwardly a relatively short time after the upward movement of thehammer member has taken place.

Spring 41 biases the ring member 37 to a position such as that shown inFIGURE '1 wherein the firusto conical sealing surface 35 of hammermember 34 will sealingly engage the frusto conical sealing surface 36 ofthe ring member 37 when the casing 12 is in its elevated position.

In the device illustrated in the drawings and above described, the toolassembly comprises the main tool bit 23 and a chopping bit 27 whichcooperates therewith to provide a chopping action along with the rotaryscraping and pounding action provided by the blade members 24, 24.Instead of using the pounding and scraping main tool bit 23, a two-coneroller rock bit may be employed in conjunction with the chopping bit 27,within the spirit of the present invention.

While a specific embodiment of an improved well drilling device of therotary hammer type has been disclosed in the foregoing description, itwill be understood that various modifications within the spirit of theinvention may occur to those skilled in the art. Therefore, it isintended that no limitations be placed on the invention except asdefined by the scope of the appended claims.

What is claimed is:

1. In a well drilling device, a vertical main casing, a bearing collarsecured in the lower end of said main casing, a first tool-supportingtube extending slidably through said bearing collar, a first tool bitsecured to said tube, a second tool bit slidably engaged with said firsttool bit and extending transversely thereto, being slidable verticallyrelative to said first tool bit, a second tool-supporting tube securedto the top end of said second tool bit and extending slidably in saidfirst tool-supporting tube, an annular hammer secured on the top end ofsaid second tool-supporting tube, a depending pressure fluid conduitsecured axially in the top of said main casing and extending slidablythrough said hammer and into said second tool-supporting tube, anannular valve member surrounding said second tool-supporting tubesubjacent said hammer and being sealingly engageable with the hammer,means sealing the annular valve member with respect to the main casingto define a substantially fluid-tight space beneath the valve member,spring means connecting said valve member to a subjacent portion of thefirst tool-supporting tube and being sufficiently yieldable to allowupward force to be at times transmitted to the hammer member by saidvalve member, said subjacent portion and said tool-supporting tube beingformed with fluid passages, means blanking said passages when the maincasing is moved upwardly relative to the toolsupporting tubes, meansestablishing communication between said space beneath said annular valvemember and said pressure fluid conduit through said passages when themain casing is moved downwardly relative to said tubes, the top portionof the main casing being provided with a vent passage, and means toconnect said pressure fluid conduit to a source of fluid under pressure,whereby said hammer is elevated by the pressure fluid acting upwardly onsaid valve member, disengaging the hammer from said valve member,allowing the hammer to subsequently drop and allowing the pressure fluidand the hammer to drive the second tool bit downwardly relative to thefirst tool bit.

2. In a well drilling device, a vertical main casing, a bearing collarsecured in the lower end of said main casing, a first tool-supportingtube extending slidably through said bearing collar, a first tool bitsecured to said tube, said first tool bit comprising a pair ofdiametrically opposed blade members formed with a vertical guide slottherebetween, a second tool bit slidably engaged with said first toolbit and extending transversely thereto in said guide slot, beingslidable vertically relative to said first tool bit, a secondtool-supporting tube secured to the top end of said second tool bit andextending slidably in said first tool-supporting tube, an annular hammersecured on the top end of said second tool-supporting tube, a dependingpressure fluid conduit secured axially in the top of said main casingand extending slidably through said hammer and into said secondtool-supporting tube, an annular valve member surrounding said secondtool-supporting tube subjacent said hammer and being sealinglyengageable with the hammer, means sealing the annular valve member withrespect to the main casing to define a substantially fluidtight spacebeneath the valve member, spring means connecting said valve member to asubjacent portion of the first tool-supporting tube and beingsufficiently yieldable to allow upward force to be at times transmittedto the hammer member by said valve member, said subjacent portion andsaid tool-supporting tubes being formed with fluid passages, meansblanking said passages when the main casing is moved upwardly relativeto the toolsupporting tubes, means establishing communication betweensaid space beneath said annular valve member and said pressure fluidconduit through said passages when the main casing is moved downwardlyrelative to said tubes, the top portion of the main casing beingprovided with a vent passage, and means to connect said pressure fluidconduit to a source of fluid under pressure, whereby said hammer iselevated by the pressure fluid acting upwardly on said valve member,disengaging the hammer from said valve member, allowing the hammer tosubsequently drop and allowing the pressure fluid and the hammer todrive the second tool bit downwardly relative to the first tool bit.

3. In a well drilling device, a vertical main casing, a bearing collarsecured in the lower end of said main casing, a first tool-supportingtube extending slidably through said bearing collar, a first tool bitsecured to said tube, said first tool bit comprising a pair ofdiametrically opposed blade mebers formed with a vertical guide slottherebetween, a second tool bit slidably engaged with said first toolbit and extending transversely thereto in said guide slot, beingslidable vertically relative to said first tool bit, a secondtool-supporting tube secured to the top end of said second tool bit andextending slidably in said first tool-supporting tube, an annular hammersecured on the top end of said seeond tool-supporting tube, a dependingpressure fluid conduit secured axially in the top of said main casingand extending slidably through said hammer and into said second tool-supporting tube, a valve guide sleeve secured to the top portion of saidfirst tool-supporting tube and being slidably and sealingly disposed inthe main casing, an annular valve member slidably and sealinglypositioned in said valve guide sleeve and surrounding said secondtool-supporting tube subjacent said hammer and being sealinglyengageable with the hammer, whereby to define a substantiallyfluid-tight space beneath the valve member, a coiled biasing springaxially mounted in said guide sleeve and connecting said valve member toa subjacent portion of the first tool-supporting tube and beingsufliciently yieldable to allow upward force to be at times transmittedto the hammer member by said valve member, said subjacent portion andsaid tool-supporting tube being formed with fluid passages, meansblanking said passages when the main casing is moved upwardly relativeto the toolsupporting tubes, means establishing communication betweensaid space beneath said annular valve member and said pressure fluidconduit through said passages when the main casing is moved downwardlyrelative to said tubes, the top portion of the main casing beingprovided with a vent passage, and means to connect said pressure fluidconduit to a source of fluid under pressure, whereby said hammer iselevated by the pressure fluid acting upwardly ,on the valve member,disengaging the hammer from said valve member, allowing the hammer tosubsequently drop and allowing the pressure fluid and the hammer todrive the second tool bit downwardly relative to the first tool bit.

References Cited in the file of this patent UNITED STATES PATENTS1,932,891 Harner ot. 31, 1933 2,085,279 Tautenhahn June 29, 19372,917,025 Dulaney Dec. 15, 1959

